Dynamic compensation device coordination control method, system and equipment for three-phase imbalance treatment of power distribution network and medium

Abstract

The invention discloses a dynamic compensation device coordination control method, system, equipment and medium for three-phase imbalance management of a power distribution network, and belongs to the technical field of power quality management and control of the power distribution network, and the method comprises the steps: collecting the three-phase electrical quantity in real time through a configuration collection device, and carrying out the reasonability verification of the collected data; calculating an unbalance degree based on the three-phase electrical quantity, and performing grade division; component decomposition is carried out on the three-phase unbalanced voltage and current to output a compensation current target value, a compensation device is configured in the power distribution network, compensation tasks are distributed, a multi-target optimization model is established, and a compensation scheme with the optimal comprehensive benefit is obtained; and establishing a short-term load prediction model, and pre-judging a three-phase imbalance change trend to carry out predictive adjustment on a compensation strategy. According to the invention, coordination and cooperation of multiple compensation devices are realized, repeated compensation and mutual interference are avoided, performance advantages of each compensation device are brought into full play, treatment efficiency is improved, dynamic adaptive compensation is realized, multi-target collaborative optimization is realized, and unbalance degree is reduced.

Description

Technical Field

[0001] This invention relates to the field of power quality management and control technology for distribution networks, specifically to a coordinated control method, system, equipment, and medium for dynamic compensation devices in the management of three-phase imbalance in distribution networks. Background Technology

[0002] With the increasing integration of single-phase loads, nonlinear loads, and distributed generation into power distribution networks, three-phase imbalance is becoming increasingly serious. Three-phase imbalance leads to a series of problems, including increased transformer losses, excessive neutral current, and reduced motor efficiency. Existing three-phase imbalance mitigation technologies have the following main shortcomings: The compensation devices operate independently and lack coordination: Traditional governance methods typically only configure a single type of compensation device, making it difficult to simultaneously address multiple issues such as reactive power, harmonics, and imbalance. Even when multiple compensation devices are installed in the same distribution network, the lack of a coordination and control mechanism leads to each device operating independently, which can easily result in unreasonable allocation of compensation capacity and mutual interference between devices, leading to poor overall compensation performance.

[0003] Static and fixed compensation control strategies cannot adapt to dynamic load changes: Existing compensation devices mostly adopt fixed parameter control strategies, with compensation capacity and targets remaining essentially unchanged after commissioning. However, distribution network loads exhibit significant time-varying characteristics, and the degree of three-phase imbalance changes dynamically over time. Fixed compensation strategies cannot track load changes, potentially leading to overcompensation under light loads and undercompensation under heavy loads, making it difficult to guarantee effective compensation throughout all time periods.

[0004] The lack of a multi-objective optimization mechanism results in low overall benefits: Three-phase imbalance management involves multiple optimization objectives, including reducing imbalance, reducing network losses, and improving voltage quality. Existing methods typically focus on only a single objective, and the lack of a multi-objective optimization mechanism leads to unsatisfactory overall economic and technical performance of the management solutions. Summary of the Invention

[0005] In view of the above-mentioned problems, the present invention is proposed.

[0006] Therefore, the present invention aims to achieve coordinated operation of multiple compensation devices, dynamic adaptive adjustment of compensation strategies, and multi-objective collaborative optimization control.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a coordinated control method for dynamic compensation devices in power distribution network three-phase imbalance management, comprising, The system collects three-phase electrical quantities in real time using data acquisition devices and verifies the rationality of the collected data. It calculates the imbalance degree based on the three-phase electrical quantities and classifies the imbalance degree into levels. The system decomposes the three-phase unbalanced voltage and current into components and outputs the target value of the compensation current. It configures compensation devices in the distribution network, assigns compensation tasks, calculates the compensation current command for the compensation devices, and sends it to the local controller of the device for execution. A multi-objective optimization model is established to obtain the compensation scheme with the best overall benefits. A short-term load forecasting model is established to predict the trend of three-phase imbalance and make proactive adjustments to the compensation strategy. The system continuously monitors the actual compensation effect and compares it with the expected target, and makes feedback adjustments based on the deviation.

[0008] As a preferred embodiment of the dynamic compensation device coordination control method for three-phase imbalance management in distribution networks as described in this invention, the real-time acquisition of three-phase electrical quantities includes real-time acquisition of three-phase voltage and current data through smart energy meters and power quality monitoring devices configured at key nodes of the distribution network. Data acquisition employs a unified clock synchronization mechanism to control the sampling time error at each measuring point, calculate the effective value of the acquired data and perform rationality verification, identify abnormal data, and initiate the data repair program.

[0009] As a preferred embodiment of the dynamic compensation device coordination control method for three-phase imbalance management in the power distribution network described in this invention, the step of classifying the imbalance degree includes calculating the voltage imbalance degree and current imbalance degree based on the collected effective value data of three-phase voltage and current. The degree of imbalance is defined as the ratio of the maximum deviation to the average value of the three-phase voltage. The degree of imbalance is classified into levels, including mild imbalance, moderate imbalance, and severe imbalance.

[0010] As a preferred embodiment of the dynamic compensation device coordination control method for three-phase imbalance management of distribution network described in this invention, the target value of the output compensation current includes decomposing the three-phase unbalanced voltage and current into positive sequence, negative sequence and zero sequence components using the symmetrical component method. Determine the target value of the compensation current that the compensation device needs to generate, taking into account the capacity limit of the compensation device. If the calculated compensation current exceeds the rated capacity of the device, it should be reduced proportionally. Define the compensation depth coefficient and calculate the actual output compensation current.

[0011] As a preferred embodiment of the dynamic compensation device coordination control method for three-phase imbalance management in distribution networks described in this invention, the allocation compensation task includes configuring SVG compensation devices and APF compensation devices in the distribution network, and obtaining the compensation current... Decomposed into active and reactive components: In the formula, To compensate for the active component of the current, To compensate for the reactive component of the current, The power factor angle for negative sequence current; Based on the device characteristics, SVG is responsible for reactive power compensation, and APF is responsible for active power compensation. The task allocation ratio is defined as follows: In the formula, Assign a percentage of tasks to SVG. This represents the current available capacity of the SVG. This represents the current available capacity of the APF. The SVG compensation current command is The compensation current command of the APF is When any device reaches its capacity limit, the excess capacity is shared by another device. A capacity over-limit flag is defined as follows: In the formula, and These are the rated currents of the SVG and APF, respectively. when When the overloaded portion of the device is transferred proportionally to another device, the capacity reallocation algorithm is triggered. After the allocation is completed, and As control commands for each device, they are sent to the device's local controller via the communication interface to drive the power devices to generate corresponding compensation current.

[0012] As a preferred embodiment of the dynamic compensation device coordination control method for three-phase imbalance management in distribution networks as described in this invention, the multi-objective optimization model includes: establishing a multi-objective optimization model to obtain the compensation scheme with the best comprehensive benefits; the optimization objective functions include minimizing imbalance, minimizing network loss, and minimizing voltage deviation; and defining a comprehensive objective function: In the formula, F is the comprehensive objective function. For the imbalance objective, For network loss targets, For voltage deviation target, These are the corresponding weighting coefficients; The objective function of unbalance is calculated using the compensated current unbalance, the objective function of network loss is calculated considering line resistance loss, and the objective function of voltage deviation is calculated using the deviation of three-phase voltage from the rated value. The constraints of the optimization model include the capacity constraints of the compensation device and the voltage safety constraints. ; The particle swarm optimization algorithm is used to solve the multi-objective optimization problem. The algorithm iteratively determines the optimal compensation current allocation scheme to minimize the comprehensive objective function F. The allocation result is corrected according to the optimal compensation current command obtained from the solution, so as to achieve multi-objective collaborative optimization.

[0013] The beneficial effects of the preferred technical solution in this embodiment of the invention are as follows: A comprehensive optimization model is constructed, encompassing multiple objectives such as imbalance, network loss, and voltage quality. Under the premise of satisfying the capacity constraints of the compensation device and the safety constraints of the power grid, the optimal compensation scheme with the best overall benefits is sought. Through a dynamic weight adjustment mechanism, the various optimization objectives are flexibly balanced under different operating scenarios.

[0014] As a preferred embodiment of the dynamic compensation device coordination control method for three-phase imbalance management in distribution networks as described in this invention, the short-term load forecasting model includes: establishing a short-term load forecasting model, predicting the trend of three-phase imbalance changes, training a time series forecasting model using historical data, extracting the time series characteristics of the three-phase current, predicting the three-phase current values ​​for the next 15 minutes, and calculating the imbalance degree for future periods based on the predicted three-phase currents. In the formula, To predict the degree of imbalance, For the predicted three-phase average current, This is the predicted value of phase A current. This is the predicted value for phase B current. This is the predicted value for phase C current; When the difference between the predicted imbalance and the current imbalance exceeds a threshold, the compensation strategy is adjusted in advance: like The compensation current target value is recalculated based on the prediction results, and the operating points of SVG and APF are adjusted in advance. The prediction adjustment module is executed every 5 minutes, forming a rolling optimization mechanism. The prediction error is evaluated by comparing the actual measured value with the predicted value. When the prediction error exceeds 15% for multiple consecutive times, the prediction model is retrained and the model parameters are updated using the latest historical data. , , ; The beneficial effects of the preferred technical solution in this embodiment of the invention are as follows: Based on real-time operating data of the distribution network, the type and degree of three-phase imbalance are dynamically identified, and the working mode and compensation parameters of the compensation device are adaptively adjusted. A load forecasting model is established to predict the trend of imbalance changes in advance, ensuring that good mitigation effects are maintained under various load conditions.

[0015] After the compensation device is put into operation, the actual compensation effect is continuously monitored and compared with the expected target. Feedback adjustments are made based on the deviation. The three-phase voltage and current after compensation are collected in real time, and the actual imbalance after compensation is calculated. Define the evaluation indicators for compensation effectiveness: In the formula, To compensate for efficiency, To compensate for the previous imbalance; when If the compensation effect is deemed unsatisfactory, the deviation between the actual compensation current and the commanded value is calculated: In the formula, and The current tracking errors of SVG and APF are respectively. and This represents the actual output current of the device. and To optimize the obtained instruction values; A PI controller is used to adjust the compensation current according to the tracking error. The updated compensation current command is sent to the SVG device to drive the output adjustment. When the compensation efficiency reaches more than 90% for 10 consecutive cycles, it is determined that the current control parameter setting is reasonable and remains unchanged; otherwise, the parameter adaptive adjustment mechanism is triggered.

[0016] The beneficial effects of the preferred technical solution in this embodiment of the invention are as follows: A coordinated control framework is established for multiple compensation devices such as SVG and APF, and compensation tasks are rationally allocated based on the performance characteristics and capacity limitations of each device. Through real-time communication and data sharing, the devices form an organic whole, avoiding redundant compensation and mutual interference, fully utilizing the compensation capabilities of each device, and improving the overall governance effect.

[0017] Another objective of this invention is to provide a dynamic compensation device coordination and control system for managing three-phase imbalance in power distribution networks.

[0018] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a dynamic compensation device coordination control system for three-phase imbalance management in power distribution networks, comprising: a data acquisition module, an imbalance calculation module, a symmetric component decomposition module, a compensation task allocation module, a multi-objective optimization module, and a dynamic adjustment module; The data acquisition module collects three-phase electrical quantities in real time by configuring an acquisition device and verifies the rationality of the collected data. The unbalance calculation module calculates the unbalance based on the three-phase electrical quantities and classifies the unbalance into levels. The symmetrical component decomposition module decomposes the three-phase unbalanced voltage and current into components and outputs the target value of the compensation current. The compensation task allocation module configures compensation devices in the distribution network, allocates compensation tasks, calculates compensation current commands for the compensation devices, and sends them to the local controller of the devices for execution. The multi-objective optimization module establishes a multi-objective optimization model to obtain a compensation scheme with optimal comprehensive benefits. The dynamic adjustment module establishes a short-term load forecasting model, predicts the trend of three-phase imbalance changes, makes proactive adjustments to the compensation strategy, continuously monitors the actual compensation effect and compares it with the expected target, and makes feedback adjustments based on the deviation.

[0019] The present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, characterized in that the processor executes the computer program to implement the steps of the dynamic compensation device coordination control method for the three-phase imbalance management of the power distribution network.

[0020] The present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steps of the dynamic compensation device coordination control method for the three-phase imbalance management of the power distribution network.

[0021] The beneficial effects of this invention are as follows: By establishing a coordinated control framework for SVG and APF, this invention rationally allocates compensation tasks according to the characteristics of each device, realizes coordinated cooperation among multiple compensation devices, avoids duplicate compensation and mutual interference, fully leverages the performance advantages of each compensation device, and improves governance efficiency.

[0022] Based on real-time data acquisition and load forecasting, the system can dynamically adjust the compensation strategy to achieve dynamic adaptive compensation and adapt to the time-varying characteristics of the three-phase imbalance.

[0023] This invention constructs a multi-objective optimization model that includes imbalance, network loss, and voltage quality, achieving multi-objective collaborative optimization that reduces imbalance while taking into account economy and safety. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 The above is a flowchart of the overall process of a dynamic compensation device coordination control method for three-phase imbalance management in a power distribution network, provided in one embodiment of the present invention. Detailed Implementation

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] Example 1, referring to Figure 1 This is one embodiment of the present invention, which provides a coordinated control method for dynamic compensation devices in the management of three-phase imbalance in a power distribution network, comprising: S100. The three-phase electrical quantities are collected in real time by configuring a data acquisition device, and the rationality of the collected data is verified. S200: Calculate the unbalance degree based on three-phase electrical quantities and classify the unbalance degree into levels; S300 decomposes the three-phase unbalanced voltage and current into components and outputs the target value of the compensation current. S400: Configure compensation devices in the distribution network, assign compensation tasks, calculate the compensation current command of the compensation device, and send it to the local controller of the device for execution. S500. Establish a multi-objective optimization model to obtain the compensation scheme with the best overall benefits; S600. Establish a short-term load forecasting model, predict the trend of three-phase imbalance and make predictive adjustments to the compensation strategy, continuously monitor the actual compensation effect and compare it with the expected target, and make feedback adjustments based on the deviation. It should be noted that existing technologies suffer from technical defects such as poor coordination of compensation devices, insufficient adaptability of control strategies, and lack of comprehensive optimization capabilities.

[0028] Therefore, to address the aforementioned problems, through steps S100-S600, this invention uses a distribution network monitoring device to collect real-time voltage and current data for each phase, calculates the three-phase unbalance and negative sequence current component; then, based on the unbalance characteristics, it uses the symmetrical component method to decompose the positive sequence, negative sequence, and zero sequence components, and determines the compensation target; next, through a coordinated control algorithm, the compensation task is rationally allocated to devices such as SVG and APF, with SVG mainly undertaking fundamental negative sequence reactive power compensation and APF mainly undertaking harmonic and partial negative sequence active power compensation; simultaneously, a multi-objective optimization model is established to reduce the unbalance while minimizing network losses and improving voltage quality; finally, the compensation parameters are dynamically adjusted based on load forecast results to achieve predictive control, and the compensation effect is continuously optimized through real-time monitoring data feedback.

[0029] Example 2, refer to Figure 1This is one embodiment of the present invention, which provides a coordinated control method for dynamic compensation devices in the management of three-phase imbalance in a power distribution network, comprising: In this embodiment of the invention, step S100 involves configuring a data acquisition device to collect three-phase electrical quantities in real time and verifying the rationality of the collected data, including the following steps S101-S103: S101. Real-time collection of three-phase voltage and current data through smart energy meters and power quality monitoring devices configured at key nodes of the distribution network.

[0030] The acquisition device must meet the requirements of the IEEE 1159 standard, with a sampling frequency of no less than 128 points per cycle to ensure accurate capture of voltage and current waveforms.

[0031] In an embodiment of the present invention, controlling the sampling time error of each measuring point includes the following step A1: A1. Data acquisition adopts a unified clock synchronization mechanism, and the sampling time error of each measuring point is controlled within 1 millisecond; In an optional implementation, the sampling time error of each measuring point in S101 can be controlled by a simplified Network Time Protocol (NTP) synchronization mechanism. The smart energy meters and power quality monitoring devices of each measuring point are configured to connect to the local NTP server through a local area network and perform clock synchronization periodically. However, the NTP synchronization accuracy of this implementation is affected by network congestion and latency fluctuations, and cannot guarantee stable millisecond-level accuracy in the complex electromagnetic interference environment of the power distribution network.

[0032] In another optional implementation, the sampling time error of each measuring point in S101 can also be controlled by a synchronization mechanism based on hardware trigger signals. A central trigger generator is set up in the distribution network and periodic hardware trigger pulses are sent to each measuring point through a dedicated cable. Each measuring point device resets its local sampling clock according to the received pulse signal, controlling the sampling time error to within 5 milliseconds. However, this implementation relies on dedicated wiring and the transmission distance of the trigger signal is limited. In scenarios where distribution network nodes are scattered or there are terrain obstacles, the deployment and maintenance costs are high and the reliability is reduced.

[0033] Define the sampling dataset of measurement point i at time t as: In the formula, These are the instantaneous values ​​of the three-phase voltages A, B, and C, respectively. These are the instantaneous values ​​of the three-phase currents A, B, and C, respectively.

[0034] In an embodiment of the present invention, S102, calculating the effective value of the collected data, includes the following step B1: B1. Calculate the effective value of the collected data using a sliding window integration method over one power frequency cycle: In the formula, The effective value of the phase voltage is given, and T is the power frequency period, which is 20ms for a 50Hz system. B2. Effective value of current The calculation method is the same.

[0035] In an optional implementation, the RMS value calculation in S102 can be performed by selecting a complete power frequency cycle of data sequence from the real-time acquired instantaneous values ​​of three-phase voltage and current. For each phase, the square of the instantaneous values ​​of all sampling points within that cycle is calculated, then the arithmetic mean of these squares is obtained, and finally the square root of the mean is taken to obtain the RMS value of that phase. The RMS value of the current is calculated using the same steps; however, this fixed-cycle arithmetic mean method introduces errors under system frequency shifts or unsteady-state conditions because the fixed window cannot adapt to frequency changes.

[0036] In another optional implementation, the effective value calculation in S102 can also dynamically update the effective value estimate for each sampling point; calculate the square of the instantaneous value of the current sampling point, take a weighted average with the square estimate of the effective value at the previous moment, and then take the square root of the result as the current effective value. The weighting factor is preset according to the sampling frequency and system response requirements; however, this implementation method of exponential weighted moving average may produce phase delay, resulting in a lag in response to fast transient signals and affecting the real-time compensation effect.

[0037] In an embodiment of the present invention, S103, the reasonableness verification of the collected data includes the following steps C1-C2: C1. To ensure data reliability, the collected data must be validated for reasonableness. The three-phase voltage should meet the amplitude range constraints. In the formula, This is the rated phase voltage, typically 220V; C2. Data outside this range is marked as abnormal. The data repair program is started, and the data is repaired by interpolating data from previous and next time points or by extrapolating data from adjacent measurement points.

[0038] In an optional implementation, the rationality check in S103 can be based on the real-time collected three-phase current data to calculate the effective value of each phase current. Taking the rated current of the distribution network as a benchmark, the effective value of the current is usually required to be between 0.5 times and 2 times the rated value. If any phase current exceeds the range, the data of that phase is marked as abnormal. For abnormal data, a repair program is started, and the current values ​​at two normal sampling times are used for linear interpolation replacement, or the repair is calculated by referring to the current data of the same phase at adjacent measuring points. However, this implementation only focuses on the current amplitude and cannot identify the three-phase imbalance problem caused by voltage abnormality. The treatment effect is limited in scenarios with large voltage fluctuations.

[0039] In another optional implementation, the rationality check in S103 can also extract the zero-crossing time of each phase voltage waveform from the collected instantaneous values ​​of the three-phase voltage, calculate the phase angle difference between phase A and phase B, and between phase B and phase C, and set the allowable deviation range of the phase angle difference: the phase angle difference of a normal three-phase system should be 120 degrees, and the allowable deviation should not exceed ±5 degrees. If the phase angle difference between any two phases exceeds the allowable range, the relevant phase voltage data is marked as abnormal. The repair program uses the phase angle of the normal phase at the same time for symmetrical compensation adjustment, or uses historical phase angle data of the same period to replace the abnormal value. However, this implementation requires extremely high sampling synchronization accuracy, and may misjudge when the clock synchronization error is slightly large, and is not suitable for distribution network scenarios with severe harmonic interference.

[0040] Validated data is stored in a real-time database to provide basic data for subsequent imbalance calculations. The data update cycle is 1 second to ensure that the control system can respond to load changes in a timely manner.

[0041] In this embodiment of the invention, step S200 calculates the unbalance degree based on three-phase electrical quantities and classifies the unbalance degree into levels, including the following steps S201-S202: S201. Based on the collected three-phase voltage and current RMS data, calculate the voltage imbalance and current imbalance. According to the national standard GB / T15543-2008, the ratio of negative-order components to positive-order components is used to characterize the degree of imbalance. First, calculate the arithmetic mean of the three-phase voltages: In the formula, These are the effective values ​​of the three-phase voltages A, B, and C, respectively. Then calculate the deviation of each phase voltage from the average value: In the formula, This represents the maximum voltage deviation.

[0042] Voltage unbalance is defined as the ratio of the maximum deviation to the average value. In the formula, Voltage imbalance; when If the imbalance is deemed to be excessive, remedial measures need to be initiated.

[0043] The current imbalance is calculated using the same method, and the arithmetic mean of the three-phase currents is used. for: In the formula, , , These are the effective values ​​of the three-phase voltages A, B, and C, respectively. Maximum current deviation for: Current imbalance for: S202. Based on the calculated degree of imbalance, the degree of imbalance is divided into three levels: when At that time, it was classified as mild imbalance; when At that time, it was classified as moderate imbalance; when At that time, it was classified as severe imbalance; The imbalance level serves as the basis for subsequent compensation capacity allocation.

[0044] In this embodiment of the invention, step S300 decomposes the three-phase unbalanced voltage and current into components and outputs the target value of the compensation current, including the following steps S301-S303: S301. The three-phase unbalanced voltage and current are decomposed into positive sequence, negative sequence and zero sequence components by using the symmetrical component method, so as to provide a clear compensation target for the compensation device.

[0045] The phasor form of three-phase voltage is as follows: , , Decomposition is performed using a symmetric component transformation matrix; Define operator The transformation matrix is: In the formula, It is the positive sequence voltage component. It is a negative sequence voltage component. This represents the zero-sequence voltage component; for a three-phase three-wire system, the zero-sequence component is zero.

[0046] S302. The method of decomposing the symmetrical components of the current is the same as that used to obtain the positive sequence current. Negative sequence current and zero-sequence current .

[0047] Negative sequence current is the main factor causing three-phase imbalance and is also the main target of compensation devices. Therefore, the magnitude of the negative sequence current is defined as: In the formula, and These are the direct-axis and quadrature-axis components of the negative sequence current in the dq coordinate system, respectively, obtained from the abc coordinate system through the Park transformation.

[0048] The target value of the compensation current required by the compensation device should be determined. To completely eliminate the negative sequence current, the compensation current should be: In the formula, The negative sign indicates that the compensation current is opposite to the negative sequence current.

[0049] S303. In practical applications, considering the capacity limitation of the compensation device, when the calculated compensation current exceeds the rated capacity of the device, it needs to be reduced proportionally. Define the compensation depth coefficient: In the formula, To compensate for the depth coefficient, To compensate for the rated current of the device; The actual output compensation current is: This target compensation current value is used to allocate tasks among multiple compensation devices.

[0050] In this embodiment of the invention, step S400 involves configuring a compensation device in the power distribution network, assigning compensation tasks, calculating the compensation current command for the compensation device, and sending it to the local controller of the device for execution. This includes the following steps S401-S402: S401. The distribution network is equipped with two types of compensation devices: SVG and APF. The compensation tasks need to be reasonably allocated according to their respective performance characteristics. SVG has a fast response speed and is good at reactive power and fundamental negative sequence compensation. APF has strong harmonic compensation capability and can also take into account some negative sequence active power compensation.

[0051] The obtained compensation current Decomposed into active and reactive components: In the formula, To compensate for the active component of the current, To compensate for the reactive component of the current, The power factor angle is the negative sequence current.

[0052] S402. Based on the characteristics of the device, SVG mainly undertakes reactive power compensation, while APF mainly undertakes active power compensation. Define the task allocation ratio: In the formula, Assign a percentage of tasks to SVG. This represents the current available capacity of the SVG. This represents the current available capacity of the APF. The available capacity equals the rated capacity minus the currently used capacity.

[0053] The command to calculate the SVG compensation current is: The compensation current command for calculating the APF is: When a device reaches its capacity limit, the excess capacity is shared by another device. Define the capacity over-limit flag: In the formula, and These are the rated currents of the SVG and APF, respectively. when When the overloaded portion of the device is overloaded, the capacity redistribution algorithm is triggered, and the overloaded portion of the device is transferred proportionally to another device to ensure that neither device is overloaded.

[0054] After the allocation is completed, and As control commands for each device, they are sent to the device's local controller via the communication interface to drive the power devices to generate corresponding compensation current.

[0055] The two devices coordinate their operation through real-time data exchange to avoid compensation conflicts.

[0056] In this embodiment of the invention, a multi-objective optimization model is established in S500 to obtain the compensation scheme with the best overall benefit, including the following steps S501-S503: S501. Compensation control not only needs to reduce imbalance, but also needs to comprehensively consider network loss and voltage quality. Establish a multi-objective optimization model to seek the compensation scheme with the best overall benefits.

[0057] Specifically, the optimization objective functions include minimizing imbalance, minimizing network loss, and minimizing voltage deviation; Define the comprehensive objective function: In the formula, F is the comprehensive objective function. For the imbalance objective, For network loss targets, For voltage deviation target, For the corresponding assigned weight coefficients, satisfying ; The weighting coefficients are dynamically adjusted according to the operating scenario. During normal operation... Low pressure period Increase to 0.4.

[0058] The objective function for imbalance uses the compensated current imbalance: In the formula, To compensate for the current imbalance, and These are the maximum current deviation and average current after compensation, respectively. It should be noted that the three-phase current values ​​used here are the values ​​after the compensation current is superimposed.

[0059] The objective function for network loss considers line resistance loss: In the formula, This is the total loss of the three phases. It is a positive sequence current. To compensate for the residual negative sequence current, R is the single-phase line resistance. It should be noted that since the output current of the compensation device will generate additional losses on the line, this needs to be taken into account in the compensation current calculation.

[0060] The voltage deviation objective function uses the deviation of the three-phase voltage from the rated value: In the formula, The calculated results for each phase voltage after compensation are derived from the output voltage of the superimposed compensation device.

[0061] S502. The constraints of the optimization model include the capacity constraints of the compensation device, i.e., the capacity over-limit flag, and also voltage safety constraints. .

[0062] S503. The particle swarm optimization algorithm is used to solve the multi-objective optimization problem. The algorithm iteratively finds the optimal compensation current allocation scheme to minimize the comprehensive objective function F. The optimal compensation current command correction allocation result obtained by solving the problem achieves multi-objective collaborative optimization. Optimized instruction value and The order is issued to the compensation device for execution.

[0063] In this embodiment of the invention, a short-term load forecasting model is established in S600 to predict the trend of three-phase imbalance and make predictive adjustments to the compensation strategy. The actual compensation effect is continuously monitored and compared with the expected target, and feedback adjustment is made according to the deviation. This includes the following steps S601-S602: S601. In order to cope with dynamic load changes, a short-term load forecasting model is established to predict the trend of three-phase imbalance in future periods and realize the predictive adjustment of compensation strategy.

[0064] Historical data was used to train the time series prediction model, and load data of the same period in the past 30 days were collected to extract the time series features of the three-phase current. Predict the three-phase current values ​​for the next 15 minutes: In the formula, This is the predicted value of phase A current. Let A be the equivalent current value. The rate of change of phase A current is obtained by linear regression fitting of historical data. The prediction time step is set to 15 minutes; the prediction methods for phase B and phase C are the same.

[0065] Based on the predicted three-phase current, calculate the imbalance in advance for future periods: In the formula, To predict the degree of imbalance, For the predicted three-phase average current, This is the predicted value of phase A current. This is the predicted value for phase B current. This is the predicted value for phase C current.

[0066] When the difference between the predicted imbalance and the current imbalance exceeds a threshold, the compensation strategy is adjusted in advance: like Then, based on the prediction results, the target value of the compensation current is recalculated, and the operating points of SVG and APF are adjusted in advance so that the compensation device is ready before the load change, shortening the response time and avoiding instantaneous exceedance of the imbalance.

[0067] The prediction and adjustment module executes every 5 minutes, forming a rolling optimization mechanism; Prediction error is evaluated by comparing actual measurements with predicted values. When the prediction error exceeds 15% for multiple consecutive times, the prediction model is retrained, and the model parameters are updated using the latest historical data. , , This improves the accuracy of predictions.

[0068] S602. After the compensation device is put into operation, it is necessary to continuously monitor the actual compensation effect, compare it with the expected target, and make feedback adjustments based on the deviation to form a closed-loop control.

[0069] Real-time acquisition of compensated three-phase voltage and current to calculate the actual imbalance. Define the evaluation indicators for compensation effectiveness: In the formula, To compensate for efficiency, To compensate for the previous imbalance, The actual imbalance after compensation; when If the compensation effect is deemed unsatisfactory, adjustments are necessary.

[0070] Calculate the deviation between the actual compensation current and the commanded value: In the formula, and The current tracking errors of SVG and APF are respectively. and This represents the actual output current of the device. and The resulting instruction value is optimized.

[0071] A PI controller is used to adjust the compensation current based on the tracking error. In the formula, This is the adjustment amount for SVG compensation current. The proportionality coefficient is set to 0.8. The integral coefficient is set to 0.2; the adjustment method for APF is the same.

[0072] The updated compensation current command is as follows: New instructions The command is sent to the SVG device to drive it to adjust its output. This feedback adjustment process is executed once per second, ensuring that the compensation device can quickly track changes in commands and stably control the imbalance within the target range.

[0073] In an embodiment of the present invention, feedback adjustment based on deviation includes the following steps D1-D3: D1. Monitoring data is simultaneously fed back to multi-objective optimization as input for the next round of optimization, enabling continuous improvement of the control strategy.

[0074] D2. When the compensation efficiency reaches 90% or higher for 10 consecutive cycles, the current control parameters are determined. , , , , (etc.) should be set reasonably and kept unchanged; D3. Otherwise, trigger the parameter adaptive adjustment mechanism to find a better parameter combination through backtracking analysis of historical running data.

[0075] In an optional implementation, the feedback regulation in S602 can be based on the fuzzy rule-based compensation effect feedback regulation. It collects the three-phase electrical quantities after compensation in real time, calculates the actual current imbalance, and uses the compensation efficiency as an input variable. Through a membership function, the precise input value is converted into fuzzy linguistic variables, and inference is performed according to a pre-set fuzzy control rule base. The output linguistic variables obtained from the fuzzy inference are converted into precise compensation current adjustment amounts using defuzzification methods such as the centroid method. These compensation current adjustment amounts are then superimposed on the compensation current command of the previous cycle to form a new command, which is then sent to the local controllers of the SVG and APF for execution. However, the design and adjustment of fuzzy rules in this implementation rely on expert experience, requiring readjustment under different network topologies or load characteristics, and the control accuracy is lower than that of PI control based on a precise model.

[0076] In another optional implementation, the feedback regulation in S602 can also be based on a rule-based lookup table for switching compensation strategies. Two to three compensation effect levels are defined. For each level, the corresponding compensation strategy parameter set is calculated offline in advance or summarized from historical operating experience. The compensation efficiency is continuously monitored and calculated. After each fixed evaluation cycle, the current effect level is determined based on the compensation efficiency. If the current effect level differs from the previous evaluation cycle, a strategy switch is triggered. The compensation current command is recalculated using the parameters of the new strategy and directly sent to the compensation device. However, this implementation method is relatively coarse, belonging to a segmented open-loop adjustment, which cannot achieve smooth and accurate real-time tracking. When the load changes rapidly, it may lead to fluctuations in the compensation effect or a lag in response.

[0077] Example 3 is an embodiment of the present invention, which provides a dynamic compensation device coordination control method for three-phase imbalance management in power distribution networks. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0078] The experiment of this invention is based on the simulation verification of an actual 10kV distribution network in an industrial park. The distribution network is powered by a transformer with a capacity of 1600kVA and has three workshop loads connected downstream. The A phase load is mainly a resistance furnace (power 600kW), the B phase load is mainly a welding machine (power 450kW), and the C phase load is mainly lighting and air conditioning (power 350kW). The uneven distribution of the three-phase loads leads to a serious three-phase imbalance.

[0079] The distribution network is configured with one 300kVar SVG and one 150A APF. A detailed model of the distribution network, including transformers, lines, loads, and compensation devices, is built on the MATLAB / Simulink platform. The simulation lasts for 24 hours with a time step of 0.0001 seconds.

[0080] By simulating actual operating conditions by changing the load switching of each phase, parameters such as three-phase voltage, current, unbalance, and network loss before and after compensation are recorded. Simultaneously, a comparison group is set up, employing both a traditional fixed compensation strategy and an uncompensated strategy to verify the superiority of this patented method.

[0081] Validation was performed, as shown in Tables 1-3. Table 1 Comparison of the effects of three-phase imbalance control

[0082] As shown in Table 1, after adopting the method of the present invention, the voltage imbalance decreased from an average of 7.4% to 1.5%, and the current imbalance decreased from 13.7% to 2.2%, both meeting the national standard requirements (voltage imbalance <2%, current imbalance <5%). Compared with the fixed compensation strategy, the compensation efficiency of this method is improved by an average of 52%, and the advantage is more obvious at the moment of load change, reaching 59%.

[0083] Table 2. Effects of network loss and voltage quality improvement

[0084] Table 2 shows that this method reduces network losses by 37.8%, which is 16.4% more than the fixed compensation method; the three-phase voltage deviation rate is controlled within ±1.5%, which is significantly better than the ±2.8% of the fixed compensation method; the transformer negative sequence loss is reduced by 66.1%, extending the service life of the equipment; and the comprehensive power quality score reaches 91 points, entering the excellent level.

[0085] Table 3 Comparison of Dynamic Response Performance

[0086] Table 3 verifies the effectiveness of the dynamic adjustment and load forecasting mechanism; the method with forecasting function reduces the response time to 0.3 seconds, which is 92.1% faster than fixed compensation, and the unbalance exceedance time is only 0.8 seconds, which is almost negligible; the capacity utilization rate of the device is increased to 85%, giving full play to the efficiency of the compensation equipment; the load forecasting accuracy rate reaches 87.3%, providing reliable support for forward-looking control.

[0087] Example 4 is an embodiment of the present invention. The above is a schematic scheme of the coordinated control method for the dynamic compensation device of the three-phase imbalance control of the distribution network. It should be noted that the technical solution of the coordinated control system of the dynamic compensation device of the distribution network is based on the same concept as the technical solution of the coordinated control method of the dynamic compensation device of the distribution network described above. For details not described in detail in the technical solution of the coordinated control system of the dynamic compensation device of the distribution network in this embodiment, please refer to the description of the technical solution of the coordinated control method of the dynamic compensation device of the distribution network described above.

[0088] This embodiment provides a dynamic compensation device coordination and control system for three-phase imbalance management in distribution networks, including: a data acquisition module, an imbalance calculation module, a symmetric component decomposition module, a compensation task allocation module, a multi-objective optimization module, and a dynamic adjustment module; The data acquisition module collects three-phase electrical quantities in real time by configuring acquisition devices and verifies the rationality of the collected data; The unbalance calculation module calculates the unbalance based on three-phase electrical quantities and classifies the unbalance into levels. The symmetrical component decomposition module decomposes the three-phase unbalanced voltage and current into components and outputs the target value of the compensation current. The compensation task allocation module configures compensation devices in the distribution network, allocates compensation tasks, calculates the compensation current command of the compensation device, and sends it to the local controller of the device for execution. The multi-objective optimization module establishes a multi-objective optimization model to obtain the compensation scheme with the best overall benefits. The dynamic adjustment module establishes a short-term load forecasting model, predicts the trend of three-phase imbalance changes, makes proactive adjustments to the compensation strategy, continuously monitors the actual compensation effect and compares it with the expected target, and makes feedback adjustments based on the deviation.

[0089] This embodiment also provides an electronic device applicable to the dynamic compensation device coordination control method for three-phase imbalance management in power distribution networks, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the dynamic compensation device coordination control method for three-phase imbalance management in power distribution networks as proposed in the above embodiment.

[0090] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the dynamic compensation device coordination control method for three-phase imbalance management in power distribution networks as proposed in the above embodiments.

[0091] The storage medium proposed in this embodiment and the coordinated control method of the dynamic compensation device for the three-phase imbalance management of the distribution network proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0092] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0093] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A coordinated control method for dynamic compensation devices in power distribution network three-phase imbalance management, characterized in that: include, By configuring a data acquisition device to collect three-phase electrical quantities in real time, the rationality of the collected data is verified. The unbalance is calculated based on the three-phase electrical quantities, and the unbalance is classified into different levels. The three-phase unbalanced voltage and current are decomposed into components, and the target value of the compensation current is output. In the power distribution network, configure compensation devices, assign compensation tasks, calculate the compensation current command of the compensation device, and send it to the local controller of the device for execution. Establish a multi-objective optimization model to obtain the compensation scheme with the best overall benefits; Establish a short-term load forecasting model to predict the trend of three-phase imbalance and make proactive adjustments to the compensation strategy. Continuously monitor the actual compensation effect and compare it with the expected target, and make feedback adjustments based on the deviation.

2. The coordinated control method for dynamic compensation devices in the three-phase imbalance management of distribution networks as described in claim 1, characterized in that: The real-time acquisition of three-phase electrical quantities includes the real-time acquisition of three-phase voltage and current data through smart energy meters and power quality monitoring devices configured at key nodes of the distribution network. Data acquisition employs a unified clock synchronization mechanism to control the sampling time error at each measuring point, calculate the effective value of the acquired data and perform rationality verification, identify abnormal data, and initiate the data repair program.

3. The coordinated control method for dynamic compensation devices in the three-phase imbalance management of distribution networks as described in claim 2, characterized in that: The classification of unbalance includes calculating voltage unbalance and current unbalance based on the collected effective values ​​of three-phase voltage and current. The degree of imbalance is defined as the ratio of the maximum deviation to the average value of the three-phase voltage. The degree of imbalance is classified into levels, including mild imbalance, moderate imbalance, and severe imbalance.

4. The coordinated control method for dynamic compensation devices in the three-phase imbalance management of distribution networks as described in claim 3, characterized in that: The target value of the output compensation current includes decomposing the three-phase unbalanced voltage and current into positive sequence, negative sequence and zero sequence components using the symmetrical component method. Determine the target value of the compensation current that the compensation device needs to generate, taking into account the capacity limit of the compensation device. If the calculated compensation current exceeds the rated capacity of the device, it should be reduced proportionally. Define the compensation depth coefficient and calculate the actual output compensation current.

5. The coordinated control method for dynamic compensation devices in the three-phase imbalance management of distribution networks as described in claim 4, characterized in that: The compensation task includes configuring SVG compensation devices and APF compensation devices in the distribution network, and distributing the obtained compensation current. Decomposed into active and reactive components: In the formula, To compensate for the active component of the current, To compensate for the reactive component of the current, The power factor angle for negative sequence current; Based on the device characteristics, SVG is responsible for reactive power compensation, and APF is responsible for active power compensation. The task allocation ratio is defined as follows: In the formula, Assign a percentage of tasks to SVG. This represents the current available capacity of the SVG. This represents the current available capacity of the APF. The SVG compensation current command is The compensation current command of the APF is When any device reaches its capacity limit, the excess capacity is shared by another device. A capacity over-limit flag is defined as follows: In the formula, and These are the rated currents of the SVG and APF, respectively. when When the overloaded portion of the device is transferred proportionally to another device, the capacity reallocation algorithm is triggered. After the allocation is completed, and As control commands for each device, they are sent to the device's local controller via the communication interface to drive the power devices to generate corresponding compensation current.

6. The coordinated control method for dynamic compensation devices in the three-phase imbalance management of distribution networks as described in claim 5, characterized in that: The multi-objective optimization model includes establishing a multi-objective optimization model, obtaining the compensation scheme with the best comprehensive benefits, and defining the comprehensive objective function as follows: minimizing imbalance, minimizing network loss, and minimizing voltage deviation. In the formula, F is the comprehensive objective function. For the imbalance objective, For network loss targets, For voltage deviation target, These are the corresponding weighting coefficients; The objective function of unbalance is calculated using the compensated current unbalance, the objective function of network loss is calculated considering line resistance loss, and the objective function of voltage deviation is calculated using the deviation of three-phase voltage from the rated value. The constraints of the optimization model include the capacity constraints of the compensation device and the voltage safety constraints. ; The particle swarm optimization algorithm is used to solve the multi-objective optimization problem. The algorithm iteratively determines the optimal compensation current allocation scheme to minimize the comprehensive objective function F. The allocation result is corrected according to the optimal compensation current command obtained from the solution, so as to achieve multi-objective collaborative optimization.

7. The coordinated control method for dynamic compensation devices in the three-phase imbalance management of distribution networks as described in claim 6, characterized in that: The short-term load forecasting model includes: establishing a short-term load forecasting model, predicting the trend of three-phase imbalance, training a time series forecasting model using historical data, extracting the time series characteristics of the three-phase current, predicting the three-phase current value for the next 15 minutes, and calculating the imbalance degree in advance based on the predicted three-phase current. In the formula, To predict the degree of imbalance, For the predicted three-phase average current, This is the predicted value of phase A current. This is the predicted value for phase B current. This is the predicted value for phase C current; When the difference between the predicted imbalance and the current imbalance exceeds a threshold, the compensation strategy is adjusted in advance: like The compensation current target value is recalculated based on the prediction results, and the operating points of SVG and APF are adjusted in advance. The prediction adjustment module is executed every 5 minutes, forming a rolling optimization mechanism. The prediction error is evaluated by comparing the actual measured value with the predicted value. When the prediction error exceeds 15% for multiple consecutive times, the prediction model is retrained and the model parameters are updated using the latest historical data. , , ; After the compensation device is put into operation, the actual compensation effect is continuously monitored and compared with the expected target. Feedback adjustments are made based on the deviation. The three-phase voltage and current after compensation are collected in real time, and the actual imbalance after compensation is calculated. Define the evaluation indicators for compensation effectiveness: In the formula, To compensate for efficiency, To compensate for the previous imbalance; when If the compensation effect is deemed unsatisfactory, the deviation between the actual compensation current and the commanded value is calculated: In the formula and The current tracking errors of SVG and APF are respectively. and This represents the actual output current of the device. and To optimize the obtained instruction values; A PI controller is used to adjust the compensation current according to the tracking error. The updated compensation current command is sent to the SVG device to drive the output adjustment. When the compensation efficiency reaches more than 90% for 10 consecutive cycles, it is determined that the current control parameter setting is reasonable and remains unchanged; otherwise, the parameter adaptive adjustment mechanism is triggered.

8. A coordinated control system for dynamic compensation devices in distribution network three-phase imbalance management, employing the coordinated control method for dynamic compensation devices in distribution network three-phase imbalance management as described in any one of claims 1 to 7, characterized in that, include: Data acquisition module, imbalance calculation module, symmetric component decomposition module, compensation task allocation module, multi-objective optimization module, dynamic adjustment module; The data acquisition module collects three-phase electrical quantities in real time by configuring an acquisition device and verifies the rationality of the collected data. The unbalance calculation module calculates the unbalance based on the three-phase electrical quantities and classifies the unbalance into levels. The symmetrical component decomposition module decomposes the three-phase unbalanced voltage and current into components and outputs the target value of the compensation current. The compensation task allocation module configures compensation devices in the distribution network, allocates compensation tasks, calculates compensation current commands for the compensation devices, and sends them to the local controller of the devices for execution. The multi-objective optimization module establishes a multi-objective optimization model to obtain a compensation scheme with optimal comprehensive benefits. The dynamic adjustment module establishes a short-term load forecasting model, predicts the trend of three-phase imbalance changes, makes proactive adjustments to the compensation strategy, continuously monitors the actual compensation effect and compares it with the expected target, and makes feedback adjustments based on the deviation.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the dynamic compensation device coordination control method for three-phase imbalance management of distribution network as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the dynamic compensation device coordination control method for the three-phase imbalance management of the distribution network as described in any one of claims 1 to 7.

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